Properly prefix SemVer component versions for multi-project QA

When performing QA for a SemVer release (e.g., 13.3.7 to 13.3.8), the component version definitions would use an unprefixed SemVer tag, such as 8.51.0 for Workhorse.

When fetching component versions from GitLab EE, we need to fetch using the -ee suffixed tag (v13.3.7-ee), and then return a prefixed SemVer component ref (v8.51.0).

This also fixes the TAG_REGEX pattern which had an unqualified \w matcher for the prefix, so if it were matching against 13.5.1, it considered 1 the prefix, and 3 the major version. We now only consider v a valid tag prefix.